This invention relates in general to the handling of mail and, in particular, to an improved mail sorting machine.
The volume of mail handled daily by large businesses, institutions and governmental entities has steadily increased through the years. For example, credit card companies, utilities, mail order houses and other advertisers send and receive huge quantities of mail daily. Typically, the envelopes containing the material to be mailed are addressed and then sorted into common groups for mailing. Similarly, the mail received by such entities is commonly sorted into groups based on the subject matter of the received material. The quantity of mail handled daily by large businesses, institutions and governmental entitites has reached the point where new techniques and machines for automatically handling and sorting the incoming and/or outgoing mail more efficiently and economically must be developed.
Although several machines have been developed to assist in the handling and sorting of mail, such equipment has not proved to be satisfactory for several reasons. In particular, existing mail sorting machines are very complex in design and operation and require a large amount of space. Such machines are also costly to purchase and maintain. In addition, these machines are not very reliable and tend to fold, crumble, tear or otherwise damage the envelopes they handle. Another problem associated with prior art mail sorting machines is that they often fail to properly separate consecutive envelopes. As a result, two envelopes may be conveyed through the machine together and improperly deposited in the same sorting bin. Existing sorting machines also have the tendency to direct an envelope to the wrong bin.
A general solution of these prior art difficulties is given and described in the commonly owned U.S. patent application entitled MAIL SORTING MACHINE which was filed by Roy Akers, on Apr. 6, 1978, and given Ser. No. 900,070, now abandoned. That patent application is incorporated herein by reference for the purpose of illustrating the state of the prior art. While the mail sorting machine disclosed in that patent application represents a significant advance over the prior art, the design and operation of that machine is still fairly complex. The mail sorting machine described in the previously filed Akers patent application utilizes an array of metal bands which form a plurality of guideways for transferring the separated envelopes to their designated sorting bins. This type of transfer system requires the use of a complex sorting mechanism for introducing an envelope into its appropriate guideway.
It is therefore an object of the present invention to provide a mail sorting machine which is not only extremely reliable but also simple and economical to construct and operate.
Another object of the present invention is to provide a mail sorting machine of the character described which is capable of separating successive envelopes in a simple and effective manner. The mail sorting machine of the present invention includes an extremely reliable feed station for effectively separating the incoming stack of envelopes for sorting. A stack of envelopes is initially deposited on a magazine which conveys the envelopes toward the feed station. This feed station is comprised of a suction device which operates in conjunction with a pair of conveying belts to effectively draw the lead envelope away from the remainder of the supply and to keep this envelope in contact with the conveying belts for transfer to the rest of the sorting equipment. The suction device is comprised of a hollow box having two rectangular suction openings cut therein and a suction pump for maintaining a low pressure within the box. The suction box is located in close proximity to the incoming envelopes so that a portion of each suction opening overlaps at least a portion of the flat surface of the leading envelope. The conveying belts, on the other hand, are positioned to revolve in unison around the suction box in a direction which is perpendicular to the direction in which the letters are being advanced. Each conveying belt is positioned over a different suction opening and each belt is periodically provided with a grouping of holes with each grouping of holes in each belt being similarly positioned so that whenever a grouping of holes on one belt is positioned between its corresponding suction opening and the leading envelope, a corresponding grouping of holes on the other belt is similarly positioned. Whenever a series of these holes are positioned between its corresponding suction opening and the leading envelope, the low pressure within the box acts through this series of holes to draw the leading envelope toward the conveying belt for transfer away from the remaining stack of envelopes. By concentrating the suction force to such a limited area, the problem of vacuum bleed through is eliminated thereby facilitating separation of the envelopes by preventing the suction device from simultaneously drawing two envelopes toward the conveying belt. To further facilitate separation of the envelopes, the present invention includes a pair of jogger arms which serve to force the entire stack of mail away from the conveying belt just before the lead envelope is drawn toward the belt by the suction device. The effective result of this operation is to further reduce the tendency of the machine to simultaneously pick two separate envelopes.
Another object of the present invention is to provide a mail sorting machine of the character described which is capable of handling heavier mail due to the positive action between the conveying belts and the lead envelope which is drawn toward the belts by the suction device.
It is an additional object of the present invention to provide a mail sorting machine of the character described which utilizes a simple technique for directing an envelope to the appropriate sorting bin. Each sorting bin is provided with a unique diverter mechanism which is operable to deflect an envelope into its associated sorting bin in response to an appropriate control signal. The diverter mechanism is comprised of a deflecting gate having a wing portion protruding outward therefrom and a solenoid for controlling the position of the deflecting gate. The diverter mechanisms are arranged in pairs so that the wing portion of the deflecting gate of each mechanism form a channel through which the mail is capable of being conveyed in a vertical orientation. Each diverter mechanism responds to an appropriate control signal by moving its deflector gate to deflect the next envelope which is being conveyed through the channel formed by the diverter mechanism into the sorting bin associated with the activated diverter mechanism.
A further object of the present invention is to provide a mail sorting machine of the character described which includes a plurality of sorting bins having a unique construction which allows them to make use of the machines inherent vibratory motion to properly align the mail within each sorting bin.
Yet another object of the present invention is to provide a mail sorting machine of the character described which is simple to operate and which can be quickly and easily programmed to deliver envelopes to various selected bins.
It is yet another object of the present invention to provide a mail sorting machine of the character described wherein the envelopes are conveyed and handled in a reliable manner without being subject to folding, tearing or other damage.
Other and further objects of this invention, together with features of novelty apurtenant thereto, will appear in the course of the following description.